gsu: Error out if not running as bash-4.
[gsu.git] / funcs / gsu
1 #!/bin/bash
2 # gsu -- the global subcommand utility
3 # (C) 2006-2009 Andre Noll
4
5 _gsu_init_errors()
6 {
7 gsu_errors="
8 GSU_SUCCESS success
9 E_GSU_BAD_COMMAND invalid command
10 E_GSU_NOT_A_NUMBER not a number
11 E_GSU_SOURCE error in config file
12 E_GSU_CONFIG bad/missing config file option
13 E_GSU_BAD_CONFIG_VAR invalid config variable
14 E_GSU_NEED_VALUE value required but not given
15 E_GSU_BAD_BOOL bad value for boolian option
16 E_GSU_BAD_OPTION_TYPE invalid option type
17 E_GSU_BAD_ARG_COUNT invalid number of arguments
18 E_NO_DEFAULT missing default value
19 $gsu_errors
20 "
21 local a b i=0
22 while read a b; do
23 if test -z "$a"; then
24 continue
25 fi
26 #echo "a:$a, b: $b"
27 gsu_error_txt[i]="$b"
28 eval $a=$i
29 i=$(($i + 1))
30 done << EOF
31 $gsu_errors
32 EOF
33 }
34 export -f _gsu_init_errors
35
36 # check if $1 is a number
37 gsu_is_a_number()
38 {
39 result="$1"
40 if test "$1" -eq "$1" &> /dev/null; then
41 ret=$GSU_SUCCESS
42 else
43 ret=-$E_GSU_NOT_A_NUMBER
44 fi
45 }
46 export -f gsu_is_a_number
47
48 # Check number of arguments.
49 #
50 # Usage: gsu_check_arg_count <num_given> <num1> [<num2>]
51 #
52 # Check that <num_given> is between <num1> and <num2> inclusively.
53 # If only <num1> ist given, num2 is assumed to be infinity.
54 #
55 # Examples:
56 # 0 0 no argument allowed
57 # 1 1 exactly one argument required
58 # 0 2 at most two arguments admissible
59 # 2 at least two arguments reqired
60 #
61 gsu_check_arg_count()
62 {
63 ret=-$E_GSU_BAD_ARG_COUNT
64 if [[ $# -eq 2 ]]; then # only num1 is given
65 result="at least $2 args required, $1 given"
66 [[ $1 -lt $2 ]] && return
67 ret=$GSU_SUCCESS
68 return
69 fi
70 # num1 and num2 given
71 result="need at least $2 args, $1 given"
72 [[ $1 -lt $2 ]] && return
73 result="need at most $3 args, $1 given"
74 [[ $1 -gt $3 ]] && return
75 ret=$GSU_SUCCESS
76 }
77 export -f gsu_check_arg_count
78
79 gsu_short_msg()
80 {
81 echo "$1" 1>&2
82 }
83 export -f gsu_short_msg
84
85 gsu_msg()
86 {
87 gsu_short_msg "$_gsu_self: $1"
88 }
89 export -f gsu_msg
90
91 gsu_date_msg()
92 {
93 gsu_short_msg "$_gsu_self $(date): $1"
94 }
95 export -f gsu_date_msg
96
97
98
99 _gsu_banner_msg()
100 {
101 local txt="*** $_gsu_self --"
102 if test -z "$gsu_banner_txt"; then
103 txt="$txt set \$gsu_banner_txt to customize this message"
104 else
105 txt="$txt $gsu_banner_txt"
106 fi
107 gsu_short_msg "$txt ***"
108 }
109 export -f _gsu_banner_msg
110
111 gsu_err_msg()
112 {
113 local txt="$result" err
114
115 gsu_is_a_number "$ret"
116 if test $ret -lt 0; then
117 gsu_msg "unknown error ($ret:$txt)"
118 exit 1
119 fi
120 if test $result -ge 0; then
121 gsu_msg "unknown error ($result:$txt)"
122 exit 1
123 fi
124 err=$((0 - $result))
125 if test -n "$txt"; then
126 txt="$txt: ${gsu_error_txt[$err]}"
127 else
128 txt="${gsu_error_txt[$err]}"
129 fi
130 gsu_msg "$txt"
131 }
132 export -f gsu_err_msg
133
134 _gsu_usage()
135 {
136 gsu_short_msg "Usage: $_gsu_self command [options]"
137 }
138 export -f _gsu_usage
139
140 _gsu_available_commands()
141 {
142 result="$( (printf "help\nman\nprefs\n"; grep "^com_[a-z_]\+()" $0) \
143 | sed -e 's/^com_//' -e 's/()//' \
144 | sort \
145 | tr '\n' ' ')"
146 ret=$GSU_SUCCESS
147 }
148 export -f _gsu_available_commands
149
150 _gsu_print_available_commands()
151 {(
152 local i count
153 gsu_short_msg "Available commands:"
154 for i in $gsu_cmds; do
155 printf "$i"
156 count=$(($count + 1))
157 if test $(($count % 4)) -eq 0; then
158 echo
159 else
160 printf "\t"
161 if test ${#i} -lt 8; then
162 printf "\t"
163 fi
164 fi
165 done
166 echo
167 ) 2>&1
168 }
169 export -f _gsu_print_available_commands
170
171 export gsu_prefs_txt="
172 Print the current preferences.
173
174 Usage: prefs
175
176 Print out a list of all cmt config variables, together with their current value
177 and the default value."
178 com_prefs()
179 {
180 local i
181
182 for ((i=0; i < ${#gsu_options[@]}; i++)); do
183 local name= option_type= default_value= required=
184 local description= help_text=
185 eval "${gsu_options[$i]}"
186 eval val='"$'${gsu_config_var_prefix}_$name'"'
187 case "$required" in
188 true|yes)
189 printf "# required"
190 ;;
191 *)
192 printf "# optional"
193 ;;
194 esac
195 printf " $option_type: $description"
196 if [[ "$required" != "yes" && "$required" != "true" ]]; then
197 printf " [$default_value]"
198 fi
199 echo
200 [[ -n "$help_text" ]] && sed -e '/^[ ]*$/d; s/^[ ]*/# /g' <<< "$help_text"
201 printf "$name=$val"
202 [[ "$val" == "$default_value" ]] && printf " # default"
203 echo
204 done
205 }
206 export -f com_prefs
207
208 export gsu_man_txt="
209 Print the manual.
210
211 Usage: man"
212
213 com_man()
214 {
215 local equal_signs="=================================================="
216 local minus_signs="--------------------------------------------------"
217 local com num
218
219 echo "$_gsu_self (_${gsu_banner_txt}_) manual"
220 echo "${equal_signs:0:${#_gsu_self} + ${#gsu_banner_txt} + 16}"
221 echo
222
223 sed -e '1,/^#\{70,\}/d' -e '/^#\{70,\}/,$d' $0 -e 's/^# *//'
224 echo "----"
225 echo
226 echo "$_gsu_self usage"
227 echo "${minus_signs:0:${#_gsu_self} + 6}"
228 printf "\t"
229 _gsu_usage 2>&1
230 echo "Each command has its own set of options as described below."
231 echo
232 echo "----"
233 echo
234 echo "Available commands:"
235
236 _gsu_available_commands
237 for com in $result; do
238 num=${#com}
239 if test $num -lt 4; then
240 num=4
241 fi
242 echo "${minus_signs:0:$num}"
243 echo "$com"
244 echo "${minus_signs:0:$num}"
245 $0 help $com
246 echo
247 done
248 ret=$GSU_SUCCESS
249 }
250 export -f com_man
251
252 export gsu_help_txt="
253 Print online help.
254
255 Usage: help [command]
256
257 Without arguments, print the list of available commands. Otherwise,
258 print the help text for the given command."
259
260 com_help()
261 {
262 local a b
263 if test -z "$1"; then
264 _gsu_banner_msg 2>&1
265 _gsu_usage 2>&1
266 # sed is magic, baby
267 (printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
268 printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
269 printf "com_prefs()\n$gsu_prefs_txt" | head -n 4; echo "--"
270
271 grep -A 2 "^com_\([a-zA-Z_0-9]\+\)()" $0) \
272 | grep -v -- '--' \
273 | sed -e '/^com_\([a-zA-Z_0-9]\+\)()/bs' \
274 -e 'H;$!d;x;s/\n//g;b' \
275 -e :s \
276 -e 'x;s/\n//g;${p;x;}' \
277 | sed -e 's/^com_\([a-zA-Z_0-9]\+\)()#*/\1\t/' \
278 | sort \
279 | while read a b; do
280 printf "$a\t"
281 if test ${#a} -lt 8; then
282 printf "\t"
283 fi
284 echo "$b"
285 done
286 echo
287 echo "Try $_gsu_self help <command> for info on <command>."
288 ret=$GSU_SUCCESS
289 return
290 fi
291 if test "$1" = "help"; then
292 echo "$gsu_help_txt"
293 ret=$GSU_SUCCESS
294 return
295 fi
296 if test "$1" = "man"; then
297 echo "$gsu_man_txt"
298 ret=$GSU_SUCCESS
299 return
300 fi
301 if test "$1" = "prefs"; then
302 echo "$gsu_prefs_txt"
303 ret=$GSU_SUCCESS
304 return
305 fi
306 ret=$GSU_SUCCESS
307 if grep -q "^com_$1()" $0; then
308 sed -e "1,/com_$1()/d" -e '/^{/,$d' -e 's/^## *//' $0
309 return
310 fi
311 _gsu_print_available_commands
312 result="$1"
313 ret=-$E_GSU_BAD_COMMAND
314 }
315 export -f com_help
316
317 # internal gsu function that syntactically checks the gsu_options array
318 # for errors and parses the config file.
319 _gsu_check_options()
320 {
321 local i conf="${gsu_config_file:=$HOME/.$gsu_name.rc}" val
322
323 for ((i=0; i < ${#gsu_options[@]}; i++)); do
324 eval "${gsu_options[$i]}"
325 eval val='"'\$$name'"'
326 eval orig_${gsu_config_var_prefix}_$name='"'${val}'"'
327 done
328
329 [[ -r "$conf" ]] && source "$conf"
330
331 for ((i=0; i < ${#gsu_options[@]}; i++)); do
332 local name= option_type= default_value= required=
333 local description= help_text=
334 local val orig_val
335
336 eval "${gsu_options[$i]}"
337
338
339 # Check name. It must be non-empty and consist of [a-zA-Z_0-9]
340 # only. Moreover it must not start with [a-zA-Z].
341
342 ret=-$E_GSU_BAD_CONFIG_VAR
343 result="name: '$name'"
344 # bash's =~ works only for 3.2 and newer, so use grep
345 echo "$name" | grep '^[a-zA-Z][a-zA-Z_0123456789]*$' &> /dev/null;
346 [[ $? -ne 0 ]] && return
347
348 eval orig_val='"'\$orig_${gsu_config_var_prefix}_$name'"'
349 if [[ -z "$orig_val" ]]; then
350 eval val='"'\$$name'"'
351 else
352 val="$orig_val"
353 fi
354 case "$required" in
355 true|yes)
356 ret=-$E_GSU_NEED_VALUE
357 result="$name"
358 [[ -z "$val" ]] && return
359 ;;
360 false|no)
361 ;;
362 *)
363 ret=-$E_GSU_BAD_BOOL
364 result="required: $required, name: $name, val: $val"
365 return
366 esac
367
368 eval ${gsu_config_var_prefix}_$name='"'${val:=$default_value}'"'
369 # Check option type. ATM, only num and string are supported
370 # Other types may be added without breaking compatibility
371 case "$option_type" in
372 string)
373 ;;
374 num)
375 gsu_is_a_number "$val"
376 [[ $ret -lt 0 ]] && return
377 ;;
378 *)
379 ret=-$E_GSU_BAD_OPTION_TYPE
380 result="$name/$option_type"
381 return
382 esac
383 done
384 ret=$GSU_SUCCESS
385 }
386 export -f _gsu_check_options
387
388 gsu()
389 {
390 local i
391
392 gsu_is_a_number "${BASH_VERSINFO[0]}"
393 if [[ $ret -lt 0 ]]; then
394 gsu_msg "fatal: failed to determine bash version"
395 exit 1
396 fi
397
398 if [[ "${BASH_VERSINFO[0]}" -lt 4 ]]; then
399 gsu_msg "fatal: This script requires at least bash 4.0"
400 exit 1
401 fi
402 _gsu_self="$(basename $0)"
403 gsu_name="${gsu_name:=$_gsu_self}"
404 gsu_config_var_prefix="${gsu_config_var_prefix:=$gsu_name}"
405 _gsu_init_errors
406 _gsu_check_options
407 if [[ "$ret" -lt 0 ]]; then
408 if [[ "$1" != "help" && "$1" != "man" ]]; then
409 gsu_err_msg
410 exit 1
411 fi
412 fi
413 _gsu_available_commands
414 gsu_cmds="$result"
415 if test $# -eq 0; then
416 _gsu_usage
417 _gsu_print_available_commands
418 exit 1
419 fi
420 arg="$1"
421 shift
422 for i in $gsu_cmds; do
423 if test "$arg" = "$i"; then
424 com_$arg "$@"
425 if test $ret -lt 0; then
426 gsu_err_msg
427 exit 1
428 fi
429 exit 0
430 fi
431 done
432 ret=-$E_GSU_BAD_COMMAND
433 result="$arg"
434 gsu_err_msg
435 _gsu_print_available_commands
436 exit 1
437 }
438 export -f gsu
439
440 # TODO: gsu_strerror: get error string